Fixes #5722.

R=golang-dev, khr, cshapiro, rsc, r
CC=golang-dev
https://golang.org/cl/12670045

Fixes #6098.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/12717043

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/12774043

use MOVW.NE instead of BEQ and MOVW.

R=golang-dev, dave, rsc, daniel.morsing
CC=golang-dev
https://golang.org/cl/7718043

This is a part of a bigger change that adds data race detection feature:
https://golang.org/cl/6456044

R=rsc, remyoudompheng
CC=gobot, golang-dev
https://golang.org/cl/6536059

Rename the first argument of CompareAndSwapT and AddT s/val/addr/
for consistency with LoadT and StoreT.

R=rsc, r, dvyukov
CC=golang-dev
https://golang.org/cl/6494112

R=rsc
CC=golang-dev
https://golang.org/cl/4977054

R=r, rsc
CC=golang-dev
https://golang.org/cl/4571059

The LDREXD and STREXD instructions require
aligned addresses, and the ARM stack is not
guaranteed to be aligned during the check.
This may cause other problems later (on the ARM
not all 64-bit pointers may be 64-bit aligned)
but at least the check is correct now.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/4564053

R=r
CC=golang-dev
https://golang.org/cl/4313051

Fixes #170.

R=gri, iant, r, r2
CC=golang-dev
https://golang.org/cl/4241041